Underwater ultrasonic thawing apparatus

ABSTRACT

An underwater ultrasonic thawing apparatus includes a thawing treatment tank where thawing treatment water; an underwater ultrasonic vibrator configured to be fixed to an inner face of the thawing treatment tank and to emit ultrasound; a temperature sensor configured to detect a temperature of the thawing treatment tank; a temperature adjuster configured to adjust the thawing treatment water to a predetermined temperature; a controller configured to control the underwater ultrasonic vibrator; and a separation and hold means configured to separate and hold a stuff to be thawed which is thrown in the thawing treatment tank and the underwater ultrasonic vibrator.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an underwater ultrasonic thawing apparatus with respect to an already frozen stuff in all fields such as a frozen food and a frozen anatomy regarding medical clinical at present when the frozen stuff is distributed, wherein the underwater ultrasonic thawing apparatus emits a plurality of frequency bands of ultrasound to the frozen stuff at an ice temperature, enables an outer hull and core thereof to be simultaneously thawed, and reproduces freshness of the frozen stuff as when it was completely frozen.

Furthermore, the underwater ultrasonic thawing apparatus of the invention is able to wash an outer surface of a thrown-in stuff and sterilize the stuff, not limited to a thawed stuff (which means “stuff to be thawed”), and to freeze the stuff as it is after washed.

2. Description of the Related Art

With respect to a current freezing technology, if an ambient environment of a stuff to be frozen is cooled with making a liquid or a gas a medium, a food of a goods can be frozen; as a normal freezing method are cited a method of storing the food for a long time in the air of a warehouse of a low temperature and freezing the food; and a technology of instantaneously freezing a fresh raw material at an ultra low temperature by liquid nitrogen of −196 degrees Celsius.

On one hand, there exists a cause of a freshness degradation of a food in a bad environment until the food is frozen. For example, a freshness degradation of a fresh fish caught just at the equator is cited, due to being exposed to an atmospheric temperature approximately 35 degrees Celsius hours and hours. Or else, there exist various causes of the freshness degradation of a food from when the food is stored for a long time in the air of a warehouse of a low temperature to when the food is frozen, for example, due to a time elapse until the packing work of sorting the food and packing it in a box.

On the other hand, as a thawing method is cited natural thawing by leaving a thawed stuff (stuff to be thawed) in the atmospheric air for a long time. Furthermore, in thawing the thawed stuff, although the stuff is exposed in the atmospheric air for a long time, moisture is vaporized from the surface of the stuff due to humidity in the atmospheric air. Then when the moisture is vaporized, the texture of the thawed stuff is destroyed and a drip flows out of the destroyed texture. With respect to this point, it is also a problem to reduce the drip. Other than the above, there exists a method of continuously flowing tap water, throwing in frozen squids, octopuses, fishes, meats, and the like, and thawing them. Furthermore, so called rapid thawing by a plasma charge radiation or an ultrasound radiation in the air is hardly different from thawing by a microwave and is not suitable for thawing fresh fishes and shells.

Then although it is known that the length of a required thawing time in the above thawing technology is not only a mere cause of a quality degradation due to the freshness degradation, but also additionally causes heavy tangible and intangible losses, the thawing technology has not progressed at all.

Furthermore, in any freezing technology described above, a person other than in charge cannot know a freezing process after a food is frozen; a consumer and a distributor perform thawing after the purchase of an already frozen stuff, and can firstly know its quality badness after they thaw the stuff.

Furthermore, in using a food the next day, even in a case of thawing the food from the previous day, there exists the food that cannot be refrozen after it is thawed; in this case there is no way other than putting the food on the shelf.

Furthermore, at present when energy saving is exhorted, it is a common target over all electric appliances to reduce their power consumption.

Furthermore, although the natural thawing in the air, which is a conventional thawing technology, is a method of making the air in the atmosphere a medium and thawing an already frozen stuff by a temperature difference, an energy transfer force is weak due to the stuff being in the air, even if various frequencies other than a magnetron heat-generation frequency are emitted, and thus, the natural thawing does not shorten the thawing time of the stuff.

Furthermore, with respect to the temperature-difference thawing where an already frozen stuff is just like being left in the air over a long time, miscellaneous bacteria and pathogenic bacteria adhered to the frozen stuff also propagate, and therefore, the temperature-difference thawing is dangerous.

In coping with this, although there exists a vacuum package to suppress the propagation of bacteria, a thawing time thereby is not shortened even if the vacuum package is applied.

In a distribution firm and a food industry, thawing is performed from the previous day, taking a long time, in prospect of a sale scheduled amount of the next day. Here, if the thawed amount is lacking, the thawing is performed while tap water is released into a sink. On one hand, with respect to the surplus of already thawed stuffs, there exist many foods that cannot be refrozen, and in this case there exists no way other than putting the stuffs on the shelf; on the other hand, with respect to instantaneous refreezing, there is no facility thereof in a general household, a shop, and the like, and there exists no way other than throwing the stuffs in a refrigerator and freezing them over ten and some hours, and therefore, a value as a food is entirely damaged.

Here, in order to solve the problems due to the conventional thawing methods, the applicant invented an underwater ultrasonic thawing apparatus. It is an apparatus for thawing a thawed stuff (stuff to be thawed) under water where a heat transfer coefficient higher than in the air. At this time the underwater ultrasonic thawing apparatus emits ultrasound to the thawed stuff thrown in water by an ultrasonic vibrator in order to promote the thawing, gives a kinetic energy to the water molecules of the stuff, and thaws the stuff by a temperature rise. Furthermore, with respect to the underwater ultrasonic thawing apparatus, because ethanol is added to water where the thawed stuff is thrown, it is also possible to sterilize the outer surface of the stuff.

However, according to the above invention, there exists a problem that the thawed stuff thrown in contacts an ultrasonic vibrator for emitting ultrasound. Therefore, there exists a problem that the ultrasound does not reach whole water, and that the thawed stuff is partial thawed.

Furthermore, even with respect to the natural thawing in the air, the thawed stuff is gradually thawed from the outer surface of the stuff toward the center, the core thereof; therefore, in order to early thaw the center portion may also be thought a method of leaving the stuff in the air where a temperature is higher; however, according to this method, the surface temperature of the stuff becomes higher and the freshness degradation occurs.

Here, ideal thawing is simultaneously thawing the center portion and outside of the thawed stuff. That is, according to the conventional thawing methods, although it is possible to perform thawing, there exists no way of enabling the center portion and outside of the thawed stuff to be simultaneously thawed.

Consequently, there is a need for an apparatus that enables the center portion and outside of the thawed stuff to be simultaneously thawed.

SUMMARY OF THE INVENTION

A first aspect of an underwater ultrasonic thawing apparatus relating to the present invention is to comprise a thawing treatment tank configured to fill thawing treatment water, an underwater ultrasonic vibrator configured to be fixed to an inner peripheral face of the thawing treatment tank and to emit ultrasound, a temperature sensor configured to detect a temperature of the thawing treatment water, a temperature adjuster configured to adjust the thawing treatment water to a predetermined temperature, a controller configured to control the underwater ultrasonic vibrator, and a separation and hold means configured to separately hold a thawed stuff (stuff to be thawed) throw-in the thawing treatment tank and the underwater ultrasonic vibrator.

According to the underwater ultrasonic thawing apparatus of the invention, even if the thawed stuff throw-in the thawing treatment tank contacts an emission place of the ultrasound of the underwater ultrasonic vibrator disposed in the thawing treatment tank, it is possible to prevent the contact place of the thawed stuff from being thawed in advance, and a vibration propagation of the ultrasound from being damaged with respect to a whole area of the thawing treatment water.

A second aspect of the underwater ultrasonic thawing apparatus relating to the invention is in the first aspect that the separation and hold means is configured to be a mesh plate covering a side face and bottom face of an inner periphery side of the thawing treatment tank with a definite distance to the side face and the bottom face.

A third aspect of the underwater ultrasonic thawing apparatus relating to the invention is in the first aspect that the separation and hold means is configured to be disposed in the thawing treatment tank and to be a mesh basket where the thawed stuff is thrown.

A fourth aspect of the underwater ultrasonic thawing apparatus relating to the invention is in the third aspect that the mesh basket is rotatable in the thawing treatment tank.

A fifth aspect of the underwater ultrasonic thawing apparatus relating to the invention is in the first aspect that the thawing treatment tank is configured to have a structure of a multilayer wall.

A sixth aspect of the underwater ultrasonic thawing apparatus relating to the invention is in the second aspect that a gap between the multilayer wall is configured to be vacuum.

A seventh aspect of the underwater ultrasonic thawing apparatus relating to the invention is in the first aspect that a plurality of the underwater ultrasonic vibrators is comprised and a part of the plurality of the underwater ultrasonic vibrators has a frequency of 25 kHz to 300 kHz and the others have a frequency of 300 kHz to 2000 kHz.

An eighth aspect of the underwater ultrasonic thawing apparatus relating to the invention is in the first aspect that the apparatus further comprises a circulation pump configured to circulate the thawing treatment water filled in the thawing treatment tank.

According to the present invention there exists the following effect.

A thawing completion time of a thawed stuff means a time when the thawing of the core portion thereof is completed; an ultrasound energy emitted from an underwater ultrasonic vibrator is transferred from the outer surface to core portion, center, of the thawed stuff by also being assisted by thawing treatment water of high conductivity covering around the thawed stuff.

Furthermore, the ultrasound energy received by the outer surface of the thawed stuff is larger than that of the core portion thereof, and the outer surface starts to firstly thaw. Then because the texture of an already thawed food decreases in the conductivity of the ultrasound energy, its outer surface already thawed becomes a cause of delaying the thawing speed of the core; whereas, the outer surface receives the energy more than necessary at a time when the core is completely thawed.

Consequently, according to the present invention, by delaying the thawing speed of the outer surface of the thawed stuff with the thawing treatment water of a temperature of approximately −5 degrees Celsius around the stuff, it is intended to prevent not only the freshness of the stuff from being degraded due to the outer surface being overheated, but also the thawing speed of the core portion from being delayed.

Furthermore, although thawing is conventionally in the air which is a heat transfer medium, in the present invention the thawing is adapted to be in the water where a heat transfer coefficient is higher than in the air. Thus it is possible to perform short-time thawing of the thawed stuff without using the natural thawing in the air that needs a longer time in thawing the stuff, and thus, it is not necessary to thawing the stuff in advance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a whole section view and partial front view of an underwater ultrasonic thawing apparatus relating to an embodiment of the present invention.

FIG. 2 is a plan section view of the underwater ultrasonic thawing apparatus shown in FIG. 1.

FIG. 3 is a whole section view and partial front view of the underwater ultrasonic thawing apparatus, where a separation and hold means is changed from that of FIG. 1, relating to the embodiment.

FIG. 4 is a whole section view and partial front view of the underwater ultrasonic thawing apparatus, where thawing is performed by using a metal mesh conveyor, relating to the embodiment.

FIG. 5 is a whole section view and partial front view of the underwater ultrasonic thawing apparatus, where a refrigerant is used, relating to the embodiment.

BEST MODE(S) FOR CARRYING OUT THE INVENTION

Next will be described an underwater ultrasonic thawing apparatus 1 relating to an embodiment of the present invention.

With respect to the underwater ultrasonic thawing apparatus 1 shown in FIG. 1 relating to the embodiment, a thawing treatment tank 10 including underwater ultrasonic vibrators 11 provided on inner faces thereof and a thawing treatment tank lid 12 configured to close an opening of the tank 10 are attached to be freely opened and closed. Furthermore, the underwater ultrasonic thawing apparatus 1 comprises a controller 14 configured to control an operation of the underwater ultrasonic vibrators 11, a temperature adjuster 30 configured to adjust a temperature of thawing treatment water 20 filled in the thawing treatment tank 10, and circulation pumps 31 configured to circulate the thawing treatment water 20 adjusted to a predetermined temperature by the adjuster 30. Furthermore, the underwater ultrasonic thawing apparatus 1 comprises mesh plates 15 as a separation and hold means.

Here, a shape and size of the underwater ultrasonic thawing apparatus 1 are free. Thus with respect to a home use, it is possible to change the shape, depending on a freezer built-in type, a sink built-in type, and a desk-top small type; and with respect to a business use, depending on an installation place, a thawing treatment application, a physical property, an operation control, and the like.

Furthermore, although the shape of the thawing treatment tank 10 is no object, the tank 10 preferably has a heat insulation structure because it prevents the temperature of the thawing treatment water 20 filled in the tank 10 from rising. Here, as the heat insulation structure, it is cited to make the structure a multilayer wall and to make a gap between the wall to be vacuum.

A frequency of the underwater ultrasonic vibrators 11 is assumed to be from 25 kHz to 2000 kHz. Although there exists an individual difference, a range of 20 Hz to 20 kHz, which is a human audible sound band width, is not used from a viewpoint of its influence on a human body. On one hand, if the frequency is higher, a heat conversion of an ultrasound vibration energy is larger; it is difficult to maintain the ice thawing temperature of the thawing treatment water 20 against the temperature rise of the thawed stuff 2, and therefore, the frequency of the underwater ultrasonic vibrators 11 is assumed up to 2000 kHz. Furthermore, not less than two kinds of the underwater ultrasonic vibrators 11 may be disposed which are different in frequency.

With respect to the underwater ultrasonic vibrators 11, a plurality of the vibrators 11 controlled by the controller 14 are matched with respective areas and shapes of inner faces of the thawing treatment tank 10 and side faces of a floating prevention protrusion 13, and are disposed on the inner faces and the side faces.

The thawing treatment water 20 is water made by adding ethanol to pure water by 15% in volume. Thus the thawing treatment water 20 does not freeze even if a temperature thereof is −5 degrees Celsius; therefore, it is possible to thaw a thawed stuff (stuff to be thawed) 2 in the water 20 of an ice temperature.

Furthermore, although miscellaneous bacteria adhered to the thawed stuff 2 are sterilized by ethanol added to the thawing treatment water 20, if any of a chlorine or ozone addition device and an underwater ultraviolet germicidal lamp 16 is installed, a further sterilization effect may be achieved.

Furthermore, although not shown, a thermistor of a 0.25-degree-Celsius-difference control is used as a temperature sensor from a viewpoint of avoiding a chattering; however, when a bimetal whose detection error is approximately 4 degrees Celsius is used, it is requested to add ethanol to pure water by 20% in volume and to keep the thawing treatment water 20 not to freeze until −10 degrees Celsius.

Furthermore, when the thawed stuff 2 floats up which is thrown in the ethanol water of the thawing treatment water 20, a thawing effect by the underwater ultrasonic vibrators 11 is reduced. In order to prevent this, the thawing treatment tank lid 12 is provided with the floating prevention protrusion 13 protruding toward the thawing treatment tank 10.

Furthermore, when the floating prevention protrusion 13 is provided with the underwater ultrasonic vibrators 11, the mesh plates 15 are preferably provided also on the side faces of the protrusion 13, respectively, in order to prevent the thawed stuff 2 floated up from being partially thawed.

Then because the thawing start temperature of the thawed stuff 2 is approximately −5 degrees Celsius, the temperature of the thawing treatment water 20 is made −8 degrees Celsius, and the underwater ultrasonic vibrators 11 give the stuff 2 a vibration energy having a heat generation energy equivalent to −5 degrees Celsius.

Here, with respect to the underwater ultrasonic vibrators 11 emitting the vibration energy, a selection of its emission frequency is not limited, and the frequency may be widely selected. Furthermore, because a wavelength band of an underwater wave energy (vibration energy) is different from that of a magnetron microwave, the energy does not influence on the living organism of the thawed stuff 2 and does not also damage the freshness of the stuff 2 during frozen storage.

From a viewpoint of maintaining the freshness of the thawed stuff 2, it is requested to keep the temperature of the thawing treatment water 20 to be −5 degrees Celsius and the temperature is set to be −5 degrees Celsius by the temperature adjuster 30; however, it is requested to provide the circulation pumps 31 in order to uniform the temperature of the thawing treatment water 20 in the thawing treatment tank 10.

Although a separation and hold means shown in FIG. 1 is the mesh plates 15, the means is not limited thereto. When the mesh plates 15 are attached, it is possible to uniformly thaw whole of the thawed stuff 2 by making a distance between the underwater ultrasonic vibrators 11 and the plates 15 to be 20 mm. Other than these, an underwater rotation mesh basket 17 may be installed. Thus because the underwater rotation mesh basket 17 where the thawed stuff 2 is thrown is rotated, it is possible to avoid a partial radiation of ultrasound. Or else, if a metal mesh conveyor 18 is provided, the thawed stuff 2 is thawed while it is moved, it is possible to avoid a partial exposure thereof to ultrasound.

Thus described, in accordance with the separation and hold means such as the mesh plates 15, the underwater rotation mesh basket 17, and the metal mesh conveyor 18, it is possible to prevent the thawed stuff 2 thrown in the thawing treatment tank 10 from being partially exposed to ultrasound, and therefore, the stuff 2 is not partially thawed.

Other than these, if the underwater ultraviolet germicidal lamp 16 is installed in the thawing treatment water 20, safety is further enhanced. Instead of the underwater ultraviolet germicidal lamp 16, any one of an ozone sterilization device and the water 20 where chlorine is added is also available.

Furthermore, in order to utilize each rotation drive motor used in the temperature adjuster 30, the circulation pump(s) 31, the underwater rotation mesh basket 17, and the metal mesh conveyor 18, the rotation shaft of a generator 40 is connected to the drive shaft of each rotation drive motor by a belt and a pulley. Thus it is possible to suppress power consumption.

According to the present invention, the following effects are obtained.

According to the invention, because thawing is performed in the thawing treatment water 20 of not more than an ice temperature by a vibration energy through ultrasound, the freshness of the thawed stuff 2 is not degraded. Furthermore, a thawing time of the thawed stuff 2 may be shortened. The thawed stuff 2 is not limited to a fresh fish and does not depend on kinds such as meats and fresh vegetables.

Here, if nigiri sushi where shari, wasabi, and neta are put is packed in vacuum and rapidly frozen, the nigiri sushi is a frozen stuff; according to the present invention, the nigiri sushi may be thawed in 15 minutes, and it is possible to eat sushi hand-rolled in Japan in each country of the world.

Furthermore, when the frozen stuff is eaten soon after it is thawed, it is possible to thaw the stuff in ten minutes if the temperature of the thawing treatment water 20 is made a room temperature or approximately 35 degrees Celsius.

Furthermore, even when there occurs an already thawed stuff not used notwithstanding being thawed from the previous day, it is possible to freeze the stuff below −50 degrees Celsius if ethanol is added to pure water by 59.999% in volume with respect to the thawing treatment water 20.

As an experiment result, a frozen and vacuum-packed sea bream of 30 cm length from head to tail was thawed; the temperature of the thawing treatment water 20 was set as −5 degrees Celsius, and it took approximately 15 minutes when the core temperature of the sea bream reached −5 degrees Celsius. However, two kinds of the underwater ultrasonic vibrators 11 were used, and the frequencies of the vibrators 11 were 35 kHz and 1500 kHz.

Furthermore, according to the conventional natural thawing in the air, there exist a texture denaturalization due to the moisture vaporization from the surface of a thawed stuff (stuff to be thawed) and a drip flowing out of the stuff; whereas, according to the present invention, there does not occur such a problem.

In such a restaurant kitchen, it is possible to thaw an already frozen stuff after receiving the order of a customer and to avoid the stuff from being, as conventionally, thawed in advance from the previous day. Furthermore, it is possible to avoid an already frozen stuff from being excessively thawed, and the stuff unable to be refrozen from being disposed, and also to avoid an economical loss.

In accordance with the underwater wave thawing by the ultrasonic vibration according to the present invention, it is possible to wash away miscellaneous bacteria and other substances adhered to the surface of the thawed stuff 2 and also possible to sterilize the surface by ethanol, and thus possible to perform the hygiene management of the stuff 2.

Also with respect to a pesticide adhered to fresh vegetables and unable to be seen by naked eyes, it is possible to wash away the pesticide adhered to the surface of the vegetables because they are thawed in the ethanol water by ultrasound, and it also leads to the safety enhancement.

With respect to the black smear of shell of a peony shrimp due to its thawing, if the shrimp is thawed according to present invention, it is possible to thaw it in a state of a red color.

With respect to a frozen crab with shell, although there exists no thawing treatment way other than normally performing a boiling treatment, it is possible according to the present invention to thaw the crab in 15 minutes and also to provide delicious crab sashimi because the meat of the crab is not boiled.

Conventionally, if an abalone is once frozen and thawed, it cannot be made sushi neta because of its meat hardening; however, according to the present invention, even if a living abalone is frozen and thawed, its meat is not hardened; and therefore, it is possible to provide it as sushi neta.

Furthermore, it is possible to thaw cut meat of such a sardine and a flounder in a matter of minutes of if a core temperature of the cut meat is approximately −5 degrees Celsius. In addition to this, because it is also possible to freeze and thaw a garnish of sashimi, wasabi, a dark or light soy sauce, and the like, a sashimi set may be distributed to each country of the world.

By utilizing rotations of motors used in any of the underwater rotation mesh basket 17, the metal mesh conveyor 18, the temperature adjuster 30, and the circulation pump(s) 31 that are the components of the present invention, it is also possible to generate power.

A material of the thawing treatment tank 10 is preferably stainless steel of any one of SUS (Special Use Steel) 304 and SUS 316, reinforced plastics is also available.

Furthermore, when the present invention is used in home, it is also possible to configure not to install the temperature adjuster 30 in order to downsize the underwater ultrasonic thawing apparatus 1 of the invention; it is because even if the thawing treatment water 20 is in a state of a normal temperature, it is possible to thaw the thawed stuff 2. However, in order to maintain the freshness of the thawed stuff 2, it suffices to throw an ice refrigerant 19 in the thawing treatment water 20 and to make its temperature an ice temperature. 

1. An underwater ultrasonic thawing apparatus having a thawing treatment tank where thawing treatment water is filled, an underwater ultrasonic vibrator configured to be fixed to an inner face of the thawing treatment tank and to emit ultrasound, a temperature sensor configured to detect a temperature of the thawing treatment tank, a temperature adjuster configured to adjust the thawing treatment water to a predetermined temperature, and a controller configured to control the underwater ultrasonic vibrator, the apparatus comprising: a separation and hold means configured to separate and hold a stuff to be thawed, which is thrown in the thawing treatment tank, and the underwater ultrasonic vibrator.
 2. The underwater ultrasonic thawing apparatus according to claim 1, wherein the separation and hold means is configured to be a mesh plate to cover a side face and bottom face of an inner periphery side of the thawing treatment tank with a definite distance to the side face and the bottom face.
 3. The underwater ultrasonic thawing apparatus according to claim 1, wherein the separation and hold means is configured to be disposed in the thawing treatment tank and to be a mesh basket in which the stuff to be thawed is thrown.
 4. The underwater ultrasonic thawing apparatus according to claim 3, wherein the mesh basket is configured to be a rotatable mesh basket in the thawing treatment tank.
 5. The underwater ultrasonic thawing apparatus according to claim 1, wherein the thawing treatment tank is configured to have a structure of a multilayer wall.
 6. The underwater ultrasonic thawing apparatus according to claim 2, wherein a gap between the multilayer wall is configured to be vacuum.
 7. The underwater ultrasonic thawing apparatus according to claim 1, wherein a plurality of the underwater ultrasonic vibrators is comprised and a part of the plurality of the underwater ultrasonic vibrators has a frequency of 25 kHz to 300 kHz and the others have a frequency of 300 kHz to 2000 kHz.
 8. The underwater ultrasonic thawing apparatus according to claim 1 further comprising a circulation pump configured to circulate the thawing treatment water filled in the thawing treatment tank. 